Are you just surfing the web - or will you be gaming on the web?
While the best connection is wired ethernet, if that is not possible (you can pay an electrician about $200 to install a cable for you), there are several options: (in order best to worst)
1) Powerline adapter - this works great for some people - you plug in two adapters - one by the router, the other by the computer, and the house wiring is used to connect the ethernet cables.
2) MOCA adapters - similar to powerline, except it uses the cable TV wiring to connect the devices.
3) Wireless - suggested installation would be a card/USB device that has a cable that runs from the computer to the antenna (you can place it about 6-12 feet from the computer).
Wireless of any kind is an inexact science - as any obstruction (walls, floors, furniture, electrical wiring, heating/air conditioning vents, plumbing, etc) will diminish the signal. You may get better results with a PC adapter, you may get better results with the range extender....(the access point is to add a wireless connection point to a wired hub that doesn't have wireless).
I have known people that spend a lot more than $200 to get a usable connection - and other paid $40 for cheap powerline adapters that worked great. Gaming on the web or streaming video (i.e. Netflix or other HD source) is going to need the best connection possible, while reading the news on the web may not need that much of a connection.